Once the speech was under way, Mr Bush said the country had in recent weeks seen the emotions stirred by immigration put on display as millions of immigrants and supporters took to the street to protest against plans to criminalise illegal immigrants.

He said the US had not been "in full control of its borders", allowing illegal migrants to "sneak across, and millions have stayed".

But he said the vast majority were "decent people who work hard, support their families, practise their faith, and lead responsible lives".

He said his reform objectives included:

Securing US borders: The number of border guards would rise by 6,000 to 18,000, and new hi-tech detection measures including hi-tech fences, new border patrol roads, and motion sensors would be installed along the 2,000-mile (3,200km) southern border.

A temporary worker programme which would match "honest immigrants" with jobs that employers could not find Americans to do. The workers would have to return to their country of origin after a specified time.

New ID cards for legal foreign workers, to include biometric technology, would allow employers to verify they were hiring legal workers.

Providing illegal immigrants with a chance of citizenship. Mr Bush said applicants would have to pay a penalty for breaking the law, pay back taxes, learn English, and would have to "wait in line" behind legal migrants.

Encouraging immigrants to assimilate, to learn English "and embrace our common identity as Americans".

On border security, Mr Bush said 6,000 National Guards would be sent to the southern border for one year while extra border guards were trained, but that they would not undertake direct law enforcement.

Detention facilities would be increased, and legal procedures speeded up, so that illegal immigrants could be quickly deported.

On allowing long-term illegal immigrants a "path to citizenship", Mr Bush said this was "not an amnesty" but a "rational middle ground between granting an automatic path to citizenship for every illegal immigrant and a programme of mass deportation".

Fierce debate

In his address, Mr Bush referred to concerns raised by Mexico's President Vicente Fox, saying the US "is not going to militarise the southern border".

But Mexico's foreign ministry expressed doubt in a statement, saying: "We have to express our concern that these actions are not accompanied by enough progress in the legislative process."

Mr Bush appealed to Congress to help him pass his plans into law. The whole two-year package will cost about $1.9 billion.

The immigration issue has sparked fierce debate in the US and is high on the agenda as Republicans seek to retain control of Congress in November's mid-term elections. Some lawmakers have questioned whether the deployment of the National Guard would overstretch the US military.